Klebsiella Meningitis as the Initial Presentation of Macroprolactinoma: A Case Report

Abstract

Introduction: Gram negative bacterial meningitis is a rare initial presentation of a macroprolactinoma. Meningitis in these cases is likely caused by a defect in the sellar floor from surgical manipulation or treatment with a dopamine agonist causing rapid shrinkage of a tumor. Patients generally have headaches as the predominant symptom. Our case is an illustration of where meningitis is caused by a transsphenoidal surgery and where meningitis is the presenting symptom to diagnosing a macroprolactinoma.Case presentation: The patient is a 20-year old African female with history of transsphenoidal surgery over one year ago, who presents with headache associated with subjective fevers, nausea, and vomiting. The patient states that she had similar headaches for the past 2 years but not to this severity. She reports that when she was in her country one year ago she had an unknown surgery through her nose that helped the headaches for a short period of time. She recalls having increasingly irregular periods over the past year and milky discharge from her breasts.Results: Physical exam was significant for nuchal rigidity. CT scan showed large sellar mass and MRI was consistent with likely pituitary adenoma. The patient’s presentation was suspicious for meningitis, so a lumbar puncture was performed, and CSF analysis was consistent with bacterial meningitis. The patient was started on broad spectrum antibiotics until CSF cultures returned showing Klebsiella pneumoniae sensitive to ceftriaxone. Further testing showed very high prolactin levels. Endocrinology was consulted and agreed the tumor was a pituitary macroadenoma, most likely a prolactinoma due to her laboratory findings and symptoms of menstrual irregularity and galactorrhea. The patient was treated with Cabergoline 0.5 mg two times per week.Conclusion: Bacterial meningitis, especially when caused by gram negative organisms is a rare presentation of a pituitary macroprolactinoma. Thorough history taking, and prompt diagnostic evaluation is crucial, especially when medical records cannot be obtained. Treatment of both conditions quickly and simultaneously is important. The case also illustrates that how treating a prolactinoma can result in complications such as meningitis not just immediately after surgery but in any stage of treatment.